If Hamlet is the actor’s Holy Grail, the English accent is his Waterloo. With the exception of Gwyneth Paltrow, very few American actors can master it; instead, they generally fall somewhere between the ear-splitting (Keanu Reeves in Dracula) and the inexplicable (Dick Van Dyke in Mary Poppins).

In Harold Pinter’s Old Times, currently playing at Shakespeare Theatre Company, Holly Twyford proves she can add another feather to her already plume-laden cap: She does a British accent exceptionally well. Twyford plays Anna, an enigmatic and vaguely threatening visitor who calls upon old friend Kate (the luminous Tracy Lynn Middendorf) and Kate’s husband, Deeley (Steven Culp), setting off a typically Pinterian power struggle as Deeley and Anna spar for Kate’s affections. “Oh, how the ghost of you clings,” Deeley sings at one point, in a clue as to Anna’s status just as she threatens to usurp him completely.

Old Times is short (a little over 70 minutes) but dense, and it ranks as one of Pinter’s most enigmatic plays, almost entirely defying interpretation. What stands out, therefore, is tension, and for the most part the actors (directed by Shakespeare Theatre artistic director Michael Kahn) do a good job of conveying it. As the lights go up, we see Deeley and Kate facing the audience, unmoving, while Anna stands between them, her back to the audience. It’s a visual reminder of how her character comes between them, both literally and metaphorically, and it’s also nicely chilling.

Anna remains in that position until she turns around and is suddenly present in the room, recalling past adventures with Kate and obviously irritating Deeley, whose static life is upended by her presence. The pair become engaged in a battle of wills, singing snatches of songs to Kate and trading barbs. “How courageous and sensible of you both to stay permanently in such a silence,” says Anna pointedly. Deeley sings, “I’ve got a woman, crazy for me,” prompting a pause.

The truth behind the three characters has long been debated, and without giving too much away, the play becomes a treatise on the fickleness of memory. Middendorf, as Kate, does a remarkable job in expressing the character’s sexuality and the power it gives her over others; in doing so, the actress helps communicate this triangle of identities, rooted in the past. Culp, as Deeley, tends to get lost in his shaky accent, using it as an affectation that prevents him from getting to the core of his role. It’s hard not to imagine how more potent the production could have been without the nuances of pronunciation to grapple with. Twyford is a gifted performer, but she occasionally veers too far into Noel Coward territory, playing for easy laughs rather than emotional complexity.

Unsettling tension is at the core of Pinter, and Walt Spangler’s set—an achingly minimalist white box—heightens the hyperreality without becoming a distraction. Toward the play’s conclusion, a Washington miracle occurred: The audience stopped coughing and watched, transfixed. Gripes about dialects aside, I doubt Michael Kahn will ever get much more of an affirmation than that.